diff options
Diffstat (limited to 'Documentation/cpusets.txt')
-rw-r--r-- | Documentation/cpusets.txt | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt index aa854b9b18cd..fb7b361e6eea 100644 --- a/Documentation/cpusets.txt +++ b/Documentation/cpusets.txt | |||
@@ -171,6 +171,7 @@ files describing that cpuset: | |||
171 | - memory_migrate flag: if set, move pages to cpusets nodes | 171 | - memory_migrate flag: if set, move pages to cpusets nodes |
172 | - cpu_exclusive flag: is cpu placement exclusive? | 172 | - cpu_exclusive flag: is cpu placement exclusive? |
173 | - mem_exclusive flag: is memory placement exclusive? | 173 | - mem_exclusive flag: is memory placement exclusive? |
174 | - mem_hardwall flag: is memory allocation hardwalled | ||
174 | - memory_pressure: measure of how much paging pressure in cpuset | 175 | - memory_pressure: measure of how much paging pressure in cpuset |
175 | 176 | ||
176 | In addition, the root cpuset only has the following file: | 177 | In addition, the root cpuset only has the following file: |
@@ -222,17 +223,18 @@ If a cpuset is cpu or mem exclusive, no other cpuset, other than | |||
222 | a direct ancestor or descendent, may share any of the same CPUs or | 223 | a direct ancestor or descendent, may share any of the same CPUs or |
223 | Memory Nodes. | 224 | Memory Nodes. |
224 | 225 | ||
225 | A cpuset that is mem_exclusive restricts kernel allocations for | 226 | A cpuset that is mem_exclusive *or* mem_hardwall is "hardwalled", |
226 | page, buffer and other data commonly shared by the kernel across | 227 | i.e. it restricts kernel allocations for page, buffer and other data |
227 | multiple users. All cpusets, whether mem_exclusive or not, restrict | 228 | commonly shared by the kernel across multiple users. All cpusets, |
228 | allocations of memory for user space. This enables configuring a | 229 | whether hardwalled or not, restrict allocations of memory for user |
229 | system so that several independent jobs can share common kernel data, | 230 | space. This enables configuring a system so that several independent |
230 | such as file system pages, while isolating each jobs user allocation in | 231 | jobs can share common kernel data, such as file system pages, while |
231 | its own cpuset. To do this, construct a large mem_exclusive cpuset to | 232 | isolating each job's user allocation in its own cpuset. To do this, |
232 | hold all the jobs, and construct child, non-mem_exclusive cpusets for | 233 | construct a large mem_exclusive cpuset to hold all the jobs, and |
233 | each individual job. Only a small amount of typical kernel memory, | 234 | construct child, non-mem_exclusive cpusets for each individual job. |
234 | such as requests from interrupt handlers, is allowed to be taken | 235 | Only a small amount of typical kernel memory, such as requests from |
235 | outside even a mem_exclusive cpuset. | 236 | interrupt handlers, is allowed to be taken outside even a |
237 | mem_exclusive cpuset. | ||
236 | 238 | ||
237 | 239 | ||
238 | 1.5 What is memory_pressure ? | 240 | 1.5 What is memory_pressure ? |
@@ -707,7 +709,7 @@ Now you want to do something with this cpuset. | |||
707 | 709 | ||
708 | In this directory you can find several files: | 710 | In this directory you can find several files: |
709 | # ls | 711 | # ls |
710 | cpus cpu_exclusive mems mem_exclusive tasks | 712 | cpus cpu_exclusive mems mem_exclusive mem_hardwall tasks |
711 | 713 | ||
712 | Reading them will give you information about the state of this cpuset: | 714 | Reading them will give you information about the state of this cpuset: |
713 | the CPUs and Memory Nodes it can use, the processes that are using | 715 | the CPUs and Memory Nodes it can use, the processes that are using |